1. Field of the Invention
This invention relates, generally, to improvements in electrolytic cells that generate chlorine gas and caustic and deliver those products to a swimming pool. More particularly, it relates to an improved to an improved means for controlling the density of the caustic liquid therein.
2. Description of the Prior Art
U.S. Pat. No. 4,613,415 to the present inventors and the references of record therein are believed to represent the most relevant prior art to this disclosure.
In that patent, a hydrometer having a color-coded neck is provided so that as the density of the caustic (sodium hydroxide) in the catholyte increases toward the end of the batch life, the hydrometer rises and the color code on the neck thereof alerts the cell owner that a fresh batch of catholyte is needed. However, no means for preventing the undesirable increase in the specific gravity of the caustic is provided in that disclosure.
More importantly, the prior art neither teaches nor suggests how the increase in specific gravity of the sodium hydroxide in the catholyte that naturally occurs after prolonged operation of the cell could be prevented.